metrictonner

Ooops. ECU. I think the tipoff was the total absence of coil input from the ECU and no injector squirt. Either the ECU was bad or something else was shutting down the ECU like, as you guys were saying, the CPS. Yet another rebuilt MJ part that didn't last long. The Standard rebuilt ECU lasted about 3 years. The 25 year old OEM is now back in. Think I'll try Cardone next. Why do the swapping? So I know that I always have a tested, working backup ready to pop in when someone says something like...you have a bad CPS. I can go right to my parts bin and pull out a good part to check it out. I also don't have to get hung up on trying to figure out if a new part really works or not. Of course this only works for people who absolutely have to have their Comanche.

My part in this topic is officially closed. Thanks for the help. Yaaas the old buggie is now running. No low battery, no open fusible links, no bad grounds, no ignition coil, no CPS, no distributor, no connection shorts, my suddenly dead...had a bad

Cruiser: I got .47 VAC and 200 ohms. This is from my OEM CPS. My store-bought one is at 215 ohms. I'm thinking the OEM is ok? Glad to hear that things are probably localized in the CPS. I'm going to check connections and all black grounds off of the ECU and if that is ok I'm going to swap the ECU back to the OEM. So you are the one with those tips? Pretty good, thanks. I've been using the wiring routing clips through 2 or 3 CPS changes already. A tip I discovered is how to install without popping out the plastic bell housing cap. Swing the CPS into position with the lower bolt already finger tightened. I have a 5-speed and when I swapped CPS's back at 130k miles the OEM was clean as a whistle. You are telling me my clutch isn't falling apart, thanks, nice to know.

The OEM Bosch lasted 23 years before I replaced it for no good reason...and I stuck it back in after the Carter failed.

There is no chance for a spark: The line from the ECU to the coil is dead. As a matter of fact, I sniffed the throttle body inlet and I don't smell any gas either. All of my fusable links have continuity. The closest I've ever come to this problem was when the vacuum hose fell off of the fuel pressure regulator...no such luck now. I agree on the MAT. The Renix manual talks about at least trying to start. The engine electrics seem to be deader than a doornail for some reason. I could say I've replaced everything that was replaceable before this happened but I know that never pulls any weight.

CPS nogo. You know, that would be hell if my MAT finally went out. That's about the only sensor there is no advertised replacement for. I don't know if it would cause total ignition failure but what are we doing for a replacement MAT nowadays?

Minuit: I ran it for a few hours a week ago. Between the off and on it got up to temp maybe three times during the day. Thanks.

A Carter lasted about a year for me and the first box had the wrong rubber spacers. I considered it a rig compared to the OEM Bosch, which you can't get anymore. It sure was a lot noisier. They all seem to be about the same generic product repackaged for the seller. Good luck.

It was running fine the last time I parked it but I don't seem to be getting any signal from the computer to the ignition coil module at all. It cranks, turns on the fuel pump and lights up the dash and accessories fine. Any suggestions?

After four or five years of running hot with crud that wouldn't be flushed I fixed everything by buying a new radiator. The install was tricky, requiring cutting and bending because no one makes an OEM anymore. Life is now good again.

If you're getting brake fluid inside leaking all over your fuse panel it's the master cylinder. If it drips on the ground it's likely the hose. It's been my experience with my 88 4.0 that there is maybe one company that makes or remanufactures a part for every supplier...if anyone makes it at all.

A slick tool for this is a long shafted paint/wallpaper scraper. Add a mason sledge. The problem is that after you do it once you will never need this stuff again. Amazing how denatured alchohol or acetone will remove the leavings but cannot be used to dissolve the mastic in place. For you 4WDers. Take a long 2x2, file off the edges on one end to round it a little, and the aforetomentioned sledge and put the tinyests of imprints on the front axle side of the pan sump at the outside edges up near the collector part of the pan, it doesn't take much of a dent, jack up the front end by the frame to suspend the front axle and the pan will slide out right around the axle. Do this bending while the pan is still bolted to the block of course. Watch you face when the pan slides out.

65 psi is oil pump relief pressure. Pressure shouldn't get above this. Did you change the sending unit with the gauges? If the pressure doesn't drop as the thing heats up you might look into what sending unit your shiney new gauge requires. There is a difference between a switch (hi-low) and a real he-man's sending unit.

With fuel injectors you get what you pay for. Mopar parts...if you can find them...are better than plastic fantasic Chinese knockoffs. If you can't get Mopar...get yours rebuilt at your local rebuild place.

Have you replaced the fan clutch with a shiney brand new REVERSE rotation one? Did you make sure it said reverse on it or have a counterclockwise arrow? You check this at the auto-parts store not mail-order. New head gasket? Did you check the head bold torque...in proper rotation? If the electric fan never fires up or you never boil over anyway, try replacing the coolant sender on the lower block because chances are you just have a sensor aging problem. Remember a 190 degree thermostat shows only slightly below the 210 degree mark on the gauge. You can verify this by turning the heater on full blast. The temperature gauge should read way lower. With the correct themostat these things appear to run hot...but nailed hot, not boiling over hot. You did check for a REVERSE rotation water pump?

A motorcycle battery is almost aways a gel-cel type so it doesn't spill when you dump your bike. It can't be emptied or filled and when the continuity reads below 12 volts it is a dead cause because it can't be brought back up to charge.

Mine has done that since day one and I always took it as a blessing. The oil pump gets primed and the oil pooled in the bottom of the bearings gets a chance to coat the journals before a firing load is applied. I crank for a second or two. Stop. Then crank until it fires (another second or two). Sometimes a third second or two crank is necessary. Total time: 3 or 4 seconds.

When mine decided to run hot a few years ago I went through the same thing until I realized that the reverse rotation fan clutch that I got off of Ebay just might be standard rotation. So I went to a local parts store and bought one with the counterclockwise arrow still printed on it. Since then I've run with the gage nailed at 190 in any kind of weather. I assume the 1989 belt is a microgroove serpentine too which requires a reverse rotation fan clutch, just make sure it is.

Empty tank for all those years? Maybe the fuel pump is trying to suck in a lot of rust. :jump:

what does this look like?

Well, well, well. I guess I can. Here are the images that go with my previous post. Sorry for the untidy appearance of the undercarrage, but you know, it is a 20 year old mud dauber. :brows:

On my 1988 AMC factory install there are 2 bolts on the crossmember and 1 on the frame (even though there are 2 bolt holes in the skid plate there is only 1 in the frame). Chrysler was doing this by 1990 so it may be different but if you are trying to align 4 bold holes and can only find 3 this may be the problem.

I cleaned the plunger seat when I put in the IAC and I ran a couple of bottles of injector cleaner. When I cleaned the throttle body I checked for fuel smell, there was none. :wall:

Brent ECU was next. All $270 of it. :redX: I popped all the relays, I'm going to pop the ECU connections tomorrow.

Correy According to Chilton 91 was the start of a new computer system. Although I must say since it started doing this I get no more lifter ticking.